It was the second bomb attack this month at the Klongtoey market and was not linked to anti-government protests elsewhere in the Thai capital, police said.

The last incident on Nov 13 wounded 13 people.

Police said the grenade was thrown after 7pm from a flyover above the rally site near Bangkok's main port. Some 300 hawkers and stall owners had gathered there to oppose a plan by landowners to redevelop the area.

'They are trying to evict us from this area,' said street vendor Somsak Yoopiam, 46. 'I was addressing the rally when a big bang sent dozens of people sprawling to the ground.' -- REUTERS